So I had bought 10 of the Polish surplus magazines from AIM recently and they looked really nice, they paint them and they look brand new. Well the problem is they fit like shit in my new Arsenal Sam7R rifle where the stock 10 round plastic magazine fit amazing. It was tight fitting in there and the release was really hard, one of them was so hard to release I though I was getting close to bending the release tab but it was fine. I took one of the magazines and took a flat file to it. I took off most of the new paint from the sides and even some of the aluminum in spots, then I filed the release tab quite a bit till it released well. Now that magazine fits really well, almost as nice as the stock plastic magazine. So is this a milled receiver issue being tighter or a surplus magazine issue with all the extra thickness from the paint?

I would say it's probably one part thick paint (I had one that was so thick it wouldn't even fit in my Mutant's magazine well, and was very snug in the AK's), and one part tolerances.

Remember that there can be quite a bit of variation in each country's magazines, there doesn't seem to be a very specific set of measurements that they went by. If it fed and fit in the gun, it was good enough.

Also note that these are surplus steel magazines, not aluminum, so if you filed all the paint off it you're gonna want to hit it with some kind of spray paint or something, otherwise you're going to have a rusty mess on your hands.

Personally I'd have filed on the magazine's locking tab instead of on the rifle's magazine release; I'd rather have one magazine with a somewhat thinner tab than a bunch of magazines that have a sloppy fit because the release is now too short.

Ok I just finished fitting 5 of my 10 magazines, I'm going to leave the other 5 as-is for a possible future stamped AK. And to clarify I'm filing the sides of the magazine, the pivot notch on the magazine and the release/lock tab on the magazine, I filed nothing on the rifle. And you are correct the magazines are steel. I oiled them after filing. I may hit them with some cold blue as it may hold up a bit better than spray paint. Its amazing what some filing can do, it transforms them in about 5 minutes from fitting like total shit to fitting like a glove, they now slide in easy, lock in positively and release well.

Ok good.  When you said "filed the release tab quite a bit" and I thought you meant the mag release on the rifle.  Don't file that.  Fit the mags to the rifle, not the rifle to the mags.  

its normal, i have had to do it to mags from just about every country.

I have read many vendors saying their mags are in spec, so the rifle must not be. Oh really?
Some buy mags that don't quite fit and it only takes a little in most cases, and they are told to file on the rifle.

I can tell you what I'm not filing on.

Not really a problem per say, these are surplus, but they don't say why. They may not fit anything without some TLC. Fit the mags to the rifle. the other way may cause problems. Knock off the paint, then coat them lightly and see how they fit. Tweak them from there.

I always take the mags that fit in all the other AKs and file the new AK's mag catch until it fits the mags.  Then any new mags have to be filed on until they fit all the AKs.  I don't want mags that are specific to certain AKs.  I think I should be able to use any mag in any AK.  It would suck to grab the wrong mags when trying to shoot and find out they don't work.

That said, I didn't have to modify the fit of my 12 Polish painted mags at all.  They fit my AKs fine.  But I have seen a few people saying they had to file paint off to get them to fit, as you did.  I did have to swap the spring in one with a Romanian mag, because that one Polish spring was binding up when I used a WeaponTech follower.  Spring swap fixed it, and both mags work fine with the other's spring.  Tolerance stacking, I guess.  

Country of origin seems to have a lot to do with fit, my Romanian mags fit my WASR & Draco better than Hungarian, Bulgarian & Yugos.

When these Polish mags were refurbished they went a little heavy on the paint. It's a known issue.

On the other hand, if the mags are loose and have wobble or flop about, people get upset about the "Sloppy Fit"...

As long as the gun feeds 100% and you can change magazines in a speedy and effective manner, then it is "O.K."...

The Polish mags fit great (just snug but not too tight) in my 7.62 Saiga (Russian) and SAR-1 (Romanian)

BIGGER_HAMMER

I only have one AK but I had to clean the lugs on all ten I ordered and I had to clean up the sides of two. All are snug as hell

If you continually find yourself fitting mags to a rifle the problem is not the mags, it's the rifle. Take a rifle with a known good magwell and measure it. Then compare with the rifle that doesn't seem to want to accept any surplus mags without fitting the mag. Chances are you'll find your problem there. I have always carefully measured and adjusted the magwell on rifles with mag issues with a small file in the area that needed attention. It's better to have a rifle that will accept damn near any surplus mag, than one that needs a dedicated set of mags to be kept with it.

Sometimes the mag IS actually the problem. This is best determined by checking how many mags the rifle will accept VS. how many it rejects, then testing the "bad" one(s) against another rifle. Most of the pre-ban stuff has a SMALL bit of play in the magwell to insure functioning with the widest possible variety of mags, as it should be. I've run both chinese and Euro. pattern mags in chinese rifles with no issues, also run chinese mags in Euro. pattern AKM and no issues there either.

IMHO, mags should all go into a big box and ALL rifles should be able to run the mags with no substantial fitting issues.

There is no mil-spec to AK mag wells. That's why there's so much variation, but that's also why they run when dragged through the mud.

One must just find the AK and mags that fit (or make them fit) the way you're OK with.